There are things you can do to scale well, that you tend to have to learn from longstanding error, that don't take a lot of time up front. You don't spend much

There are things you can do to scale well, that you tend to have to learn from longstanding error, that don't take a lot of time up front. You don't spend much time on them, and these efforts bear fruit later. Then there are things that do take a lot of time that are unwarranted. You have to avoid these. Knowing the difference is key, and this is why senior engineers should be in charge of making architectural and design choices up front, and on an ongoing basis. Of course, most businesses can't attract such people, as scalability is not common knowledge outside major internet cities :(